KLK3 and benign prostatic hyperplasia: Similarly, Arnouk et al. [30] detected a significant difference in serum PSA levels at 6 months after intraprostatic 100 U BoNT-A injection, and after 3 and 6 months after injection of BoNT-A 200  U. Also, Ding et al. [31] detected remarkable improvement in LUTS/BPH at 1 month after injection, which reached optimal levels at 6 months and was maintained for ≥1 year